React native rn fetch blob fs.readStream工作不正常

问题：

在react本机应用程序中，我使用了rn fetch blob fs.readstream。但是在读取流之后，stream.oned没有启动

我是这样用的

options = {
      title: strings('picker.q-v-pick'),
      takePhotoButtonTitle: strings('picker.tphoto'),
      chooseFromLibraryButtonTitle: strings('picker.cgallery'),
      cancelButtonTitle: strings('picker.cancel'),
      mediaType: 'video',
      durationLimit: question.question.duration,
      videoQuality: Platform.OS === 'android' ? 'medium' : 'low',

      storageOptions: {
        skipBackup: true,
        path: 'images',
      },
    };

    ImagePicker.launchCamera(options, (response) => {
      if (response.didCancel) {
        console.log('User cancelled image picker');
      } else if (response.error) {
        console.log('ImagePicker Error: ', response.error);
      } else if (response.customButton) {
        console.log('User tapped custom button: ', response.customButton);
      } else {
        RNFetchBlob.fs.readStream(response.path, 'base64').then((stream) => {
          let bitData = '';
          stream.open();
          stream.onData((chunk) => {
            // console.log(chunk);
            bitData += chunk;
          });
          stream.onEnd(() => {
            console.log('HIIi');
            console.log(bitData, 'uuu');
          });
          // response['data'] = data;
          // response['type'] = 'mp4';
          // response['fileName'] = 'videomulti.mp4';
          // setFileObject(response);
        });
      }
    });

stream.open和onData函数正在启动，但是stream.OnEnd没有启动。有人能帮我解决这个问题吗？我对这件事一无所知。多谢各位